I have a friend that has a 1990 Eagle Model 15 with a DD6V92TA in it and he said a mechanic said that it does not have a fuel modulator and has F85 injectors in it. Could the above facts be true. This unit does not smoke but the fuel milage is only 4.5 MPG. The injectors are 9F85's rather than F85's. Any input would be appreciated.

The F series was before the G series that was that last mechanical series made for the 92 series. Not sure of your turbo, but I'm guessing if you have 85's then increasing to 9G90's (most recent injector) would work. Then you'd have 330-350hp out of the engine, and properly tuned, probably will get better mileage (into the 6's). Also, the fuel modulator was also the most modern version of keeping smoke down on acceleration. The fuel modulator also made for a faster pedal response. Before that was the throttle delay-which was a small shock aborber inbetween the rockers attached to the injector rack that prevented the rack from opening to fast. While it worked, it made for a slow response engine. I had that setup on my first truck with 8V-92TA. I removed it and had a real hot rod-but could also put out a good sized puff of very black smoke. I can't remember which side it was on (I want to say the left head-or the right side as you look at the engine from the back). You can do two things, just remove it (make to much smoke) or take the piston out and drill about a 1/4" hole through the piston to increase the speed that it allows the rack to open. It'll still smoke some, but will definitely respond quicker to the pedal. Good Luck, TomC

I talked with Geoff over on BNO one time and he is using the 9G90's. He also said he gets little or no smoke, which was my biggest worry. He said he's been very happy with his engine. A question for Tom:Weren't the F series injectors he's talking about for the california emmisions certs? My FSDM doesn't go that new, it only goes up to the E series which came out in the mid '70's. Dallas

Dallas- when the California engines were in play, they used the same injectors-although there were some "C" models made that stood for clean tip, but the latest G models have all those features incorporated. Just to give you an idea, my first truck in 1980 had a 8V-92TTA (fuel squeezer) with 9A90's in them. It actually had a 79 engine in the truck which was fortunate since in 1980 they did have a California engine, but this was accomplished with retarded valve timing. Reduced the power from 435hp to 424hp. It was also the beginning of the end of that engine when they did that-it created much more heat, and worse fuel mileage. Everything went back up when they brought out the DDEC engines, but by then Detroit saw the writting on the wall in that the 2 stokers were not going to be able to meet up coming smog laws (sort of ironic that the biggest Diesel in the world is a 2 stroke-also the most fuel efficient). So that's when the Series 60 was created. It came out in 1991, if I remember right. Right away, the Series 60 got an average of one mile to the gallon better than the 8V-92TA on a same power output. By 1998, the 2 strokers were history. Considering they came out in 1938 with the natural 6-71N (also 1,2,3,4 cylinder-the V blocks came out in 1959) you could still buy a natural 6-71N in 1998 when they stopped making them. What I believe is the longest a single engine of the same configuration has been made in history. Also, it is too bad that Detroit didn't keep the versitility of the 2 strokers (run either direction, multiple configurations to your installation, on boats with 6-71's, engines could be mirrored so all maintanence was in the center with nothing servicable on the outside of the engines), need more power-add cylinders. The 20V-149 was a 8V in the center with a 6V on either side of the 8V (6+8+6=20), 24V-71TA was 2-12's together, etc. We probably won't see the likes of these engines again. Too bad. Good Luck, TomC

Thanks Tom,That made sense about the "C" models. I had thought that there had been a California engine before79-80. But with my memory lately, I have a hard time remembering my own name.Thanks for the answer you've probably helped more people than you realize.Oh, and not too many years ago I placed a bid on a Navy surplus YTB that had 4 6-149s in it. Luckily, I got outbid at the last minute. What would I do with that thing?Dallas